IC7 Nutritional Support Flashcards
What is ileum resection associated with? How can it be managed?
B12 deficiency
It is the site of B12 absorption
B12 supplementation
Which is the most absorptive part of the intestines?
Jejunum
What is the gall bladder’s function and how will diet be affected if it is removed?
Production of bile for fat digestion
Patient may need to be on long-term low-fat meals
What THREE functions do the stomach play?
Acts as an elastic reservoir
Releases intrinsic factor for B12 absorption
Secretes fluids
What syndrome is associated with removal of the stomach?
Dumping syndrome - food passes straight into the small intestine causing abdominal cramps, nausea and diarrhea
Explain how the lack of food in relation to CCK production can cause physiologic complications
CCK is released in the duodenum in response to food passage
it stimulates pancreatic contractions, bile production (liver) and bile release (gall bladder)
without food, CCK is not produced
gall bladder contraction is impaired, affecting biliary flow and causing cholestasis and jaundice
What are the 4 contributing factors to malnutrition?
- (1) Decreased intake and (2) Decreased absorption
- (3) Increased expenditure and (4) Increased losses
What are two instances that can result in (1) decreased intake?
chemotherapy causing nausea, vomiting and taste alterations which can reduce oral intake
abdominal cancers may cause ascites that exerts pressure on the GI tract, causing early satiety and reducing intake
What usually results in (2) decreased absorption?
After major surgery, resecting too much of the intestines will result in malabsorption
What usually results in (3) increased expenditure?
severe stress will increase the body’s energy consumption (e.g. surgery, trauma, sepsis, burns) to promote wound healing and help the body fight off pathogens
What usually results in (4) increased losses?
renal patients on dialysis (protein losses through dialysis machine)
What does malnutrition in healthcare result in? (cp, 4inc)
poor wound healing
compromised immune status
increased complications
impairment of organ functions (due to lack of energy)
increased mortality (more susceptible to underlying conditions)
increased use of healthcare resources
What are the 4 steps of nutritional screening and assessment?
- nutritional screening
- refer to dietician or nutritional specialist
- nutritional assessment (ABCD)
- formulation of nutritional regime
What does ABCD in nutritional assessment refer to?
A - anthropometric data (height and weight)
B - biochemical data (electrolytes and serum albumin)
C - clinical data (PMH, med hx, physical exam, edema)
D - dietary hx
How is serum albumin used as a marker for malnutrition and why is it not the most reliable?
Malnourishment (lack of protein) will cause the body to produce less albumin
Levels are also affected by inflammation and fluid overload
The 3-minNS scoring system is a malnourishment risk assessment framework validated in Asian populations.
What does the 3-minNS scoring consider? (4)
weight loss
how the nutritional intake has been
muscle from the temple
how obvious the clavicle bone is
Nutritional assessment can be assessed using Seven-point subjective global assessment (SGA) which incorporates data from ABCD. What does it consider? (6)
weight loss
dietary intake
symptoms like nausea vomiting and diarrhea
metabolic states that affect the body’s energy demands
muscle and fat wastage
edema
What does the SGA assessment tell us about the patient? What does a scoring of 1 and 7 mean?
gives us an idea of the patient’s baseline nutritional status, how urgent it is to start nutrition for the patient
1 indicates severe malnourishment
7 indicates a well nourished patient
What are the 3 main ways to calculate energy requirements?
- indirect calorimetry
- weight-based calculations
- predictive equations
How does indirect calorimetry work?
measures gas exchanged during consumption of substrates to produce required energy
What formula do weight-based calculations follow?
25-35 kcal/kg for general hospitalised patients
What else needs to be accounted for in weight-based calculations?
age
physical activity
stress factor
What do predictive equations measure and what else needs to be accounted for?
basal metabolic rate
adjust for physical activity and stress factor (age already taken into account in calculations)
How much protein do normal healthy adults require, as well as other non-CKD patients?
Normal healthy adults: 0.8 g/kg/day
Pt w trauma/surgery/burns: 1.5 to 2 g/kg/day
Pt w sepsis/critical illness: 1.5 to 2 g/kg/day or consider up to 2.5 g/kg/day
For CKD patients, how much proteins do
- patients not on dialysis,
- patients on HD/PD
- patients on CRRT
require?
not on dialysis: 0.6-0.8 g/kg/day
HD/PD: 1.2 g/kg/day
CRRT: up to 2g/kg/day
Which patient groups are EN feeds usually given to? (4)
patients who are unable to receive or tolerate adequate nutrition orally
swallowing impairment (usually post-stroke)
altered mental status (reinjury, lose consciousness)
motility disorders (DM patients with gastroparesis)
those on mechanical ventilation
Describe the properties of pre-pyloric feeding and their benefits. (4)
- more physiologic (uses GIT and maintains function)
- higher tolerance for bolus feeding
- higher tolerance for wider range of feeds (esp high osmolarity)
- can be used for venting excess fluids (lowers risk of aspiration pneumonia)
In which patient group should pre-pyloric feeding be avoided in?
patients with delayed gastric emptying
Describe the properties of post-pyloric feeding and their benefits. (3)
- smaller bore so less discomfort
- may be used in conditions that result in proximal GIT dysfunction
- lower aspiration risk
What are the downsides of post-pyloric feeding? (2)
- lower tolerance to high osmolarity enteral products as they draw water out of the intestinal lumen and cause diarrhea
- high risk of tube clogging due to smaller bore
What is the main benefit and downside benefit of nasal tubes?
can be administered at bedside
but
not very comfortable and aesthetically pleasing
What is the main benefit and downside benefit of stomy tubes?
easier to cover up, better for life-long requirement
but
requires surgical procedure that may not heal
EN feeds can be administered bolus or continuous. Outline the 4 benefits of bolus administration.
aided by gravity and mimics oral intake
more physiologic
does not require a pump
allows for greater freedom for ambulation
EN feeds can be administered bolus or continuous. Outline the 3 benefits of continuous administration.
pump assisted delivery at a constant rate
better tolerated
lower aspiration risk
What are the 4 types of EN formulas?
modular
semi-elemental
polymeric
immune-modulating or disease specific
Describe modular EN feeds and their place in therapy
contains single nutrient, usually used as a fortifier to enhance specific nutritional component (NOT meant as meal replacement)
State two examples of modular EN feeds
myotein
MCT oil
When is MCT oil usually used and how is it beneficial?
neck surgery patients to prevent chylous leak
LCTs are absorbed into the lymphatic system before the bloodstream while MCTs bypass this
Describe semi-elemental EN feeds and their place in therapy
contains partially or completely hydrolysed nutrients
for pts with:
- impaired GI function
- impaired tolerance to standard feeds (usually quite high in osmolarity so may cause diarrhea)
State an example of semi-elemental feeds
Peptamen (complete nutrition but only protein portion is hydrolysed to peptides)
Describe polymeric EN feeds and their place in therapy
contains intact macronutrients (e.g. complex sugars)
requires sufficiently functional GIT
State two examples of polymeric EN feeds
Boost isocal (usually tried first)
Resource fruit (clear feeds = no fats, digested easier)
Describe immune-modulating or disease specific EN feeds and their place in therapy
contains additions or restrictions of specific nutrients to meet needs for disease management, but may or may not meet the individual’s full nutritional needs
What is the main feature of Glucerna and which disease state is it good for use in?
Low glycemic index
Diabetes
What is the main feature of Fresubin protein energy and which disease state is it good for use in?
High protein (20g/serving)
Conditions w increased energy and protein needs
What is the main feature of Nepro HP and which disease state is it good for use in?
High protein (18g/serving)
Renal pts on dialysis or HF surgery pts on fluid restriction
What is the main feature of Nepro LP and which disease state is it good for use in?
Low protein, K and phosphate
Renal pts not on dialysis
What is the main feature of NutriFriend and which disease state is it good for use in?
Contains omega-3 fatty acids EPA/DHA
Pts w inflammatory diseases or cancer
In which type of feeding (bolus or continuous) are drug-nutrient interactions more prominent?
continuous
(not really an issue for bolus/intermittent)
What can the administration of incompatible drugs cause? (3)
precipitation
curdling/clumping or protein (acidic feeds or reflux up the tube) (fluoroquinolones chelates with Ca)
alteration of dosage forms (e.g. sustained, modified release, enteric coated)
How should drug-nutrient interactions for EN feeds be mitigated? (2)
- stopping feeding and flushing the access device before and after drug administration
- use therapeutic alternatives (convert to IR or use something that can be crushed)
What are common complications associated with feeding? (7)
- occlusion of feeding tube
- tube migration back to stomach
- infections secondary to microbial contamination
- aspiration
- nausea and vomiting
- diarrhea and constipation
- refeeding syndrome
What types of feeds are more likely to result in tube occlusion?
concentrated
high protein
fibre enriched
What are 6 strategies to maximise EN tolerance?
- monitor for tolerance after starting (abdominal pain and nausea)
- continuous feeds are better tolerated than bolus feeds
- consider prokinetic agents
- Switch to post-pyloric feeding if gastric feeding not tolerated
- Use isotonic formulas like Boost Isocal
- consider semi-elemental or elemental feeds if pt has malabsorptive issues short bowel syndrome
What are the prokinetic agents that may be considered in maximising EN tolerance?
metoclopramide
domperidone
IV erythromycin
What are the 6 benefits of using the working gut with EN feeds?
- maintains functional integrity
- undergoes FPE and promotes efficient nutrient utilisation
- maintains gallbladder function
- maintains gut-assoc and mucosal-assoc lymphoid tissue function
- less complications than PN like line-related sepsis and IFALD
- less expensive
In which pt populations is PN usually indicated for? (4)
- Paralytic ileus (trauma from abdominal surgery)
- Small bowel obstruction (due to tumour)
- High output/proximal fistula (into abdominal spacing)
- Mesenteric ischemia
Describe the catheter tip positioning for peripheral access devices for PN
located outside of the central vessels
How often do peripheral access devices require re-site
frequent (about every 72h)
What limits nutrient delivery for PN via peripheral access devices?
osmolarity and concentration (cutoff usually 900 mOSmol)
Describe the catheter tip positioning for central access devices for PN and why this is done
catheter tip is in a large bore blood vessel (e.g. distal superior VC, inferior VC, right atrium)
the high blood flow is able to instantly dilute feeds quickly to minimise pain
How often do central access devices require re-site
not as frequent as peripheral, hence better for long-term care
What are the 4 types of central access devices?
non-tunnelled central venous catheter
tunnelled central venous catheter
peripherally inserted central catheter (PICC)
port-a-cath
Compare between non-tunnelled and tunnelled central venous catheters
both are from chest to large vessels
non-tunnelled goes straight to a vessel so short distance (replace every 2 weeks), high infection risk
tunnelled goes under some distance so lower risk of infection
Describe the positioning for a peripherally inserted central catheter (PICC)
from arm to a large vessel
Describe the positioning for a port-a-cath
Which patient groups are these usually used in?
implanted near clavicle bone and requires needle insertion on every use
usually for cancer patients on chemo, replaced once every few weeks
What do PN bags typically contain?
dextrose solution
amino acid solution + electrolytes
lipid emulsion (triglycerides)
What are two things to look out for with regards to compatibility with PN bags?
calcium and phosphate are known to cause precipitation, need to add in concentrations that do not result in this
lipid emulsions are very unstable so watch out for pH
dextrose solutions are acidic (pH of about 2-3) hence amount of dextrose solution that can be added to lipids are limited
When are drug-nutrient interactions less of a concern for PN administration?
Less of a concern if administering via separate lumens of the same access device
How do the contents of Total Parenteral Nutrition (TPN) and Total Nutrition Admixtures (TNA) bags differ
TPN - without fats
TNA - 3 in 1 bag (contains everything)
How should drug-nutrient interactions be mitigated for PN feeds?
- Administer via separate peripheral IV cannula if pt has good venous access
- If needed, pause PN administration and flush access device before and after drug admin, before resuming PN infusion (esp if poor venous access, cannot insert another plug)
If PN is paused for a few hours to administer drugs to avoid drug-nutrient interactions, what should be checked?
check on the patients BG level for hypoglycemia as PN patients are not eating at all and only get sugars from their PN feeds
What are the 3 main device related complications for PN?
occlusion in IV catheter
malpositioning (pts can pull on PRICC lines and cause pain)
catheter-related bloodstream infections (CRBSI)
What are the 4 causes of occlusions in IV catheters? What are their management strategies?
- thrombosis/clotting due to insertion of foreign object (solve w heparin lock)
- inappropriate flushing techniques (shld push and pause = turbulence)
- ppts due to drug incompatibilities or crystallisation
- lipid residues (shld change admin set q24h if infusion contains lipids)
What are the 5 metabolic complications associated with feeds?
- refeeding syndrome
- hyper or hypoglycemia
- fluid overload
- intestinal failure assoc w liver disease (IFALD)
- metabolic bone disease
Describe 3 ways in which IFALD can develop
prolonged nil-by-mouth causes no CCK to be secreted, hence no gall bladder flow and impaired biliary flow
overfeeding w too much fats can cause fatty liver
LCTs are pro-inflammatory and can cause liver dmg
Describe one mitigation strategy for IFALD
SMOF diet (soybean, MCT, olive oil, fish oil)
fish oil is anti-inflammatory to counteract LCT in soybean
Outline the process of Refeeding Syndrome
pts undergoing prolonged starvation start using their body’s stores
intracellular electrolytes like potassium, magnesium and phosphate are drawn out for metabolism
the moment feeding is re-initiated, insulin is secreted, causing glucose uptake and metabolism using feeds, taking up thiamine (co-factor)
cells will also suddenly uptake K, Mg and phosphate, causing a sudden drop
What 5 things can refeeding syndrome result in?
hypokalemia
hypomagnesemia
hypophosphatemia (main hallmark)
thiamine (b1) deficiency
edema
Why are electrolyte imbalances from refeeding so dangerous?
electrolytes help maintain membrane potential, so potentially fatal
can result in arrhythmias, cardiac failure and neuromuscular complications
Patients at high risk of refeeding should be identified. What parameters are considered for this? (5)
low BMI
Unintentional weight loss
Little to no nutritional intake for 5-10d
Low levels of K, Mg, phosphate before feeding
Hx of alcohol/drug misuse (incl insulin, chemo, antacids, diuretics)
How should refeeding be managed? (5)
- check serum electrolytes at baseline
- correct deficiencies prior to feeding (defer if low)
- thiamine (b1) supplement preemptively
- initiate low and gradually increase
- monitor electrolytes as feeding progresses
